Droplet trapping and fast acoustic release in a multi-height device with steady-state flow

Rambach, R. W., Linder, K., Heymann, M. and Franke, T. (2017) Droplet trapping and fast acoustic release in a multi-height device with steady-state flow. Lab on a Chip, 17(20), pp. 3422-3430. (doi: 10.1039/C7LC00378A) (PMID:28792054)

Abstract

We demonstrate a novel multilayer polydimethylsiloxane (PDMS) device for selective storage and release of single emulsion droplets. Drops are captured in a microchannel cavity and can be released on-demand through a triggered surface acoustic wave pulse. The surface acoustic wave (SAW) is excited by a tapered interdigital transducer (TIDT) deposited on a piezoelectric lithium niobate (LiNbO3) substrate and inverts the pressure difference across the cavity trap to push a drop out of the trap and back into the main flow channel. Droplet capture and release does not require a flow rate change, flow interruption, flow inversion or valve action and can be achieved in as fast as 20 ms. This allows both on-demand droplet capture for analysis and monitoring over arbitrary time scales, and continuous device operation with a high droplet rate of 620 drops per s. We hence decouple long-term droplet interrogation from other operations on the chip. This will ease integration with other microfluidic droplet operations and functional components.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Franke, Professor Thomas
• Authors: Rambach, R. W., Linder, K., Heymann, M., and Franke, T.
• College/School: College of Science and Engineering > School of Engineering > Biomedical Engineering
• Journal Name: Lab on a Chip
• Publisher: Royal Society of Chemistry
• ISSN: 1473-0197
• ISSN (Online): 1473-0189
• Published Online: 02 August 2017